Latched cartridge



Oct. 24, 1967 5, SARNQFF ET AL 3,348,545

LATCHED CARTRIDGE Filed oat/22, 1964 INVENTORS S/an/ey J.-50m0ff John 14 Ba/anger BY 60% W ATTORNEYJ United States Patent 3,348,545 LATCHED CARTRIDGE Stanley J. Sarnoff, 7801 Woodmont Ave., Bethesda, Md. 20014, and John W. Balenger, Dayton, Ohio; said Balenger assignor to said Sarnoff Filed Oct. 22, 1964, Ser. No. 405,660 Claims. (Cl. 128-218) ABSTRACT OF THE DISCLOSURE A cartridge holder in the form of a cylindrical barrel is provided with a bearing at one end thereof and a latch at the other end thereof. A plunger rod slidable in the bearing is adapted to couple with a piston in a fluid containing cartridge which cartridge has attached thereto a hollow needle. When the plunger is in telescoped position within the barrel and a cartridge with a piston provided with a quick detachable connection is thrust against the end of the telescoped plunger the piston and plunger are coupled together and when, subsequently, the plunger is drawn back the cartridge is pulled into the barrel. The forward end of the cartridge is formed with a recess cooperating with the latch on the barrel so that the cartridge is locked to the barrel to enable the plunger to thrust the piston in the cartridge toward the needle and eject the fluid content in the cartridge through the needle while the gartridge itself is prevented from moving relative to the arrel.

This invention relates to hypodermic syringes of the type utilizing disposable, single dose cartridges and used in medicine for the parenteral injection of medicament into a patient.

It is desirable in the manipulation of such a syringe that the fresh cartridge be easily and quickly loaded into the syringe barrel and the expended cartridge be easily and quickly unloaded, particularly where the syringe is utilized to treat a long queue of patients, as in mass inoculations of Salk vaccines. Furthermore, it is imperative that notwithstanding the concomitant rapid repeated loading, unloading and reloading of the syringe barrel, the cartridge be locked in place with reference to the barrel during the expulsion of the medicament.

It is therefore an object of this invention to provide a simple means to facilitate quick loading and unloading of a cartridge with respect to a syringe barrel.

It is a further object to provide automatic means to lock the cartridge against unintentional expulsion thereof from the barrel during injection manipulation of the syringe.

Other objects will become apparent after consideration of the following specification when taken in conjunction with the accompanying drawings in which FIG. 1 is a view of the cartridge and separated parts of the syringe assembly of the invention, parts being shown in section.

FIG. 2 is a fragmentary view showing a cartridge in a latched position in the syringe.

FIG. 3 is a fragmentary view of the forward portion of a latching rod in an extended portion with reference to a surrounding sleeve.

FIG. 4 is a perspective view of a syringe with the cartridge loaded therein ready, by plunger operation, for expulsion of the medicament from the cartridge.

FIG. 5 is a perspective view of the syringe and cartridge after expulsion of the medicament and prior to cartridge unloading, and

FIG. 6 is a perspective view of the syringe and assembly, with the spent cartridge partially withdrawn from the syringe assembly.

Referring to the drawing in greater detail, a cartridge is indicated at 10, a syringe barrel at 12, and a plunger at 14.

The cartridge 10 includes a cylindrical body 16, as of glass, the rear end 18 of which is provided with a piston 20. The opposite forward end 22 of the cylindrical body is provided with a neck 24 having a rather steep wall 26 between the trough of the neck and the periphery of the cylindrical body. A collar 28 tightly surrounds the otherwise free end of the neck, this collar, in any convenient fashion, fixedly supporting a hollow needle 30. The piston 20, as of rubber, is provided with a quick detachable coupling pin 32 fixedly embedded in the piston or an integral part of the piston. The pin is formed with a conical head 34 and neck 36 to facilitate engagement with plunger parts to be described. The cartridge is filled with a medicament 38.

The barrel 12 is a hollow cylindrical body of suitable rigid material and is preferably provided with opposite longitudinal cut-outs 40 for affording a view of the cartridge contents when the cartridge is retained within the barrel. At the rear end, the barrel is provided with finger pieces 42 to be engaged by the operator when manipulating the syringe. The same end of the barrel is provided with an opening or bearing 44 to receive the plunger 14 of the syringe. The opposite or forward end of the barrel is open to receive the cartridge and is provided with a latch 46 to engage the neck portion of the cartridge and retain the cartridge within the barrel. Any suitable form of latch to accomplish this result may be employed. As here shown the latch comprises a lever 48 having anose 50 to engage the neck of the cartridge and an inclined surface 52 to enable the lever to tilt during cartridge insertion into the barrel. A spring arm 54 urges the lever to move the nose to car-tridge engaging position. The spring arm is integral with a wire 56 encircling the barrel and lying in a groove 58 therein at the forward end of the barrel, the wire passing through the lever and affording a pivot therefor. The lever lies in a slot 60 of the barrel and has a free end 62 engageable by the finger of an operator to tilt the lever about its pivot in order to free the nose from the neck of the cartridge when it is desired to expel the cartridge from the barrel.

The plunger 14 comprises a three part construction comprising a rod 64 of resilient material, as plastic, having bifurcated legs 66 biased so that they normally tend to spring apart, a spring 68 and a sleeve 70 surrounding and slidable on the rod. The forward end of the sleeve bears against a shoulder 71 on each of the bifurcated legs to limit forward movement of the sleeve and prevent inadvertent separation of rod and sleeve. The spring 68 reacts between a flared rearward end portion '72 of the sleeve and an enlargement 73 on the rod. The rear end of the rod is provided with a finger or thumb piece 74. The forward end of the sleeve may be provided with a bead 76 to prevent inadvertent withdrawal of the sleeve from the syringe barrel. The forward ends of the bifurcations are each provided with an inturned lip 75 adapted to couple behind the conical head 34 of the coupling pin, as will be explained. Due to the slotted bifurcated end construction of the rod, the sleeve may be preformed with an internal diameter very close to that of the external diameter of the rod, and slid over the rod, notwithstanding the enlarged ends of the bifurcations. The opening in the rear end of the barrel is of just sufficient size to accommodate sliding movement of the sleeve, the flared end of the sleeve abutting the rear face of the syringe barrel when the plunger is thrust forward in the barrel.

In use of the syringe, when the plunger is in the barrel with the flared end of the sleeve resting against the rear end of the barrel, pressure on the thumb piece 74 draw the bifurcations into the sleeve. In this withdrawing action, due to the close fit of the sleeve about the rod, the legs are forced toward each other and the lips on the legs engage behind the conical end of the pin, effecting a coupling between the plunger and the cartridge. Upon drawing the plunger rearwardly, the entire cartridge will be drawn, longitudinally, into the barrel and finally the nose of the lever 48 will snap behind the wall 26 of the cartridge, thus locking the cartridge against forward movement with reference to the barrel.

Upon removal of the guard about the needle (if there be one) the plunger may be thrust forward, thereby causing advancement of the piston 26 and explusion of the medicament within the cartridge through the needle. In practice, the cartridge is not quite filled, wherefore the piston is not at the rear end of the vial. This permits an aspirating movement of the piston, should such action be iesired to withdraw a sample fluid from a patient.

The cartridge may now be unloaded from the barrel by thrusting the forward end of the latch downwardly toward the axis of the needle while at the same time pressing the plunger rod forwardly. Continued movement of the rod will compress the spring, allowing spreading of the legs (as heretofore described) releasing the coupling pin of the piston and allowing the spent cartridge to be removed from the barrel.

The syringe barrel is now ready for reloading, as described heretofore.

Having thus described the invention, what is claimed 1. In combination, a cartridge having a hollow body, a piston in said body in the rear end thereof, said piston having a coupling extending rearwardly therefrom, a collar at the front end of the body supporting a hollow needle, a latch engageable recessed portion between said collar and said body and a fluid within the body between the piston and the needle, a cylindrical barrel of a length greater than the length of the cartridge, said barrel embracing the cartridge when within the barrel and having a bearing at one end thereof, said barrel also having a latch aflixed thereto engageable within the recessed portion of the cartridge, said barrel being further provided with a plunger shiftable longitudinally thereof, said plunger having a coupling element at the forward end thereof engageable with the coupling on the piston, all whereby when the plunger is in telescoped position within the barrel and the coupling between the plunger and piston is effected, the plunger may be drawn longitudinally backward in the barrel dragging the cartridge into the barrel and the cartridge and barrel may be locked to one another to enable subsequent movement of the piston relative to the cartridge while the cartridge is restrained from movement relative to the barrel.

2. The structure of claim 1 wherein the coupling on the piston comprises a pin with a shouldered head and the coupling on the plunger comprises bifurcated legs on the forward end of the plunger biased to diverge from each other, said legs having inturned lips to move to a position behind the shoulder of the head, and a sleeve slidable over the bifurcated legs to compress the lips toward each other and lock the lips and pin together.

3. The structure of claim 2, wherein the latching element on the barrel is spring biased to latching position and is provided with a portion for manual operation to release the latching element.

4. A syringe holder comprising a barrel having a bearing at the rear end thereof, a plunger slidable in said bearing and including a rod having a thumb piece on the rear end thereof and resilient divergently biased legs at the front end thereof with inturned lips on the free ends of the legs, a sleeve forming part of the plunger snugly surrounding the rod and slidable therealong, a spring to urge the sleeve toward the forward ends of the legs, an enlargement on the rear end of the sleeve to engage the barrel on the forward movement of the plunger, to limit the forward movement of the sleeve relative to the barrel, and a latch on the barrel to engage a cartridge positioned therein.

5. The structure of claim 4 wherein at least one of the legs is provided with an abutment engageable by the forward end of the sleeve to prevent inadvertent separation of the sleeve and rod.

6. A cartridge holder comprising a cylindrical barrel open at its front end and provided with a bearing at its rear end, a plunger having a bifurcated front end biased for separating movement, a sleeve slidable over said front end of said plunger, said sleeve being spring pressed forwardly with respect to the plunger to overcome the bias of the bifurcated front end, said plunger being slidable in said bearing and movable longitudinally within the barrel, means limiting the movement of the sleeve into the barrel, coupling means at the forward end of the bifurcated front end for coupling with a portion of a cartridge to draw the cartridge into the barrel upon withdrawal movement of the plunger and a pivoted latch at the forward end of the barrel for engagement with a portion at the forward end of the cartridge to prevent longitudinal movement of the cartridge after it has been drawn into the barrel.

7. The structure of claim 6 wherein the latch comprises a lever, a nose on a face of said lever opposite the axis of the barrel and spring means biasing said nose for movement in toward said axis.

8. The structure of claim 7 wherein the lever is additionally provided with an extension engageable by the hand of the operator to move the lever against its biasing force.

9. The structure of claim 8 wherein the lever is pivoted on a wire surrounding the barrel at the forward end thereof, and said wire is extended to form a spring loop engaging the lever and biasing it to latching position.

10. The structure of claim 9 wherein the lever operates through a slot in the forward end of the barrel.

References Cited UNITED STATES PATENTS 2,375,711 5/1945 Vondrak 128218 2,745,403 5/1959 Goldberg 128-218.1 2,895,474 7/1959 Reznek 128-218.1 3,115,135 12/1963 Sarnoff 1282l8.l

FOREIGN PATENTS 266,239 1/1950 Germany.

RICHARD A. GAUDET, Primary Examiner.

D. L. BAKER, Assistant Examiner. 

4. A SYRINGE HOLDER COMPRISING A BARREL HAVING A BEARING AT THE REAR END THEROF, A PLUNGER SLIDABLE IN SAID BEARING AND INCLUDING A ROD HAVING A THUMB PIECE ON THE REAR END THEREOF AND RESILIENT DIVERGENTLY BIASED LEGS AT THE FRONT END THEREOF WITH INTURNED LIPS ON THE FREE ENDS OF THE LEGS, A SLEEVE FORMING PART OF THE PLUNGER SNUGLY SURROUNDING THE ROD AND SLIDABLE THEREALONG, A SPRING TO URGE THE SLEEVE TOWARD THE FORWARD ENDS OF THE LEGS, AN 